This R21 application proposes further development of research collaborations between the University of Washington and the Instituto de Ciencias Neurologicas (ICN), the only tertiary referral center for neurologic disease in Peru. The primary goal of this grant will be to carry out necessary pilot studies to inform the planning and preparation for an application for funding of research on CNS infections affecting Peruvians, emphasizing: 1) HIV/AIDS and HIV co-infection; and 2) acute viral meningoencephalitis. Current UW-led HIV/AIDS research in Peru is supported by NIH, and from a private foundation, the Wellcome Trust, and provides an excellent foundation for development of a NeuroAIDS research program. Of particular interest will be research on the pathogenesis, clinical epidemiology, and management of AIDS-related co-infections of the CNS, including neurocysticercosis a very common and well studied condition in Peru and multidrug-resistant tuberculosis, which affects 43% of HIV-infected individuals with TB in Lima. Peru also provides a good opportunity for research on tropical meningoencephalitis, capitalizing on a recently established Global Emerging Infections Surveillance (GELS) system coordinated by the U.S. Navy Medical Research Center Detachment (NMRCD) in Peru, which provides the unique opportunity to leverage addition of sentinel surveillance for acute meningoencephalitis. In collaboration with investigators at the University of Texas-Galveston, such a system could support future research on clinical epidemiology of emerging problems in tropical viral meningoencephalitis, such as dengue and West Nile viruses, in Peru. At the beginning of the initial year, with the assistance of our External Advisory Committee, and a team of internationally-recognized co-investigators and Peruvian investigators, we will conduct research workshops to assess research, education, training, and mentoring needs and opportunities related to NeuroAIDS and acute meningoencephalitis at the ICN; followed soon by development of a preliminary research agenda and initiation of relevant pilot studies. The second year will be used to complete and analyze these pilot studies and prepare the R01 application.